A Phase I SBIR program has been completed to develop an assay system for monitoring functional fibrinogen in patients undergoing thrombolytic therapy. This prototype system can measure STAT fibrinogen with a disposable dry chemistry test card and portable analyzer using a single drop of freshly drawn whole blood sample. The study extended previous work of the past 3 years with earlier prototype fibrinogen assays. The new assay has demonstrated potential for rapid test turnaround time, greater convenience, and consequently improved diagnostic capability. Preliminary performance characteristics of the assay, potential influencing factors, and application to early determination of low fibrinogen levels in thrombolytic therapy were explored. Further development during the Phase II program will focus on: finalizing the dry chemistry test card for pilot production; calibration, standardization and translation of assay results to clinically meaningful fibrinogen values; completing the analyzer software; performing clinical comparison studies with a reference method on samples from thrombolytic therapy patients; extending comparison studies to patients with a variety of disorders; and utilizing the assay for decentralized testing by non- laboratory trained personnel in multiple test sites. Testing in clinical environments will be performed in conjunction with Research Triangle Area Medical Centers.